A curable composition including an epoxy compound, a curing agent, and a curing catalyst has widely been used in various applications such as adhesive applications, sealing applications of various electronic components, and matrix formation applications of fiber-reinforced composite materials.
There has been proposed, as a curable composition containing an epoxy compound to be used in these applications, for example, a curable composition including a (A) tetraglycidylamine type epoxy compound, (B) dicyandiamide, (C) diaminodiphenylsulfone, and a (D) urea compound, wherein viscosities at 40° C. and a curing starting temperature are within a specific range (see Patent Document 1).
Patent Document 1: Japanese Unexamined Patent Application (Translation of PCT Application), Publication No. 2013-543035